Project description:Mice with and without IFNAR expression were treated with broad-spectrum antibiotics for more than 10 days, either infected with MNV or left uninfected and then treated with 3% DSS in drinking water for 6 days. Intestinal epithelial cells were isolated from the colon and sorted and RNA extracted for RNASeq analysis. We found that mice with IFNAR expression on IEC and infected with MNV had a gene expression signature of DNA repair similar that induced by IL-22 signaling.
Project description:Colonic epithelial repair is a key determinant of health. After injury, repair initiates through phenotypic reprogramming of wounded epithelium to a regenerative state permissive for the activation of alternative stem cell populations and healing. Although cytokine signals such as interferons may help induce regenerative reprogramming, the signals that modify this state as the wound resolves remain largely unknown. Here we examined whether cytokine signaling mediated by tumor necrosis factor receptor 2 (TNFR2) influenced the wound repair process. We examined mice with targeted deletion of the Tnfrsf1b (TNFR2) gene in intestinal/colonic epithelium (Vil1::Cre;Tnfr2-f/f) and compared their transcriptional profiles to control (Tnfr2-f/f) mice. We sorted EpCAM+ (epithelial) cells from Vil1::Cre;Tnfr2-f/f and control DSS-treated mice and performed bulk RNA-Seq. Comparison of transcript expression profile before and after DSS-induced colitis in control (Tnfr2-f/f) mice revealed upregulation of pathways associated with metabolic regulation, ribosomal function, oxidative stress, TNF signaling, and focal adhesions after DSS treatment. Pathway enrichment analysis demonstrated elevated regenerative (“fetal”) intestinal signaling, reduced inflammation, and increased proliferative signaling in Vil1::Cre;Tnfr2-f/f colonic epithelium after DSS treatment. The knockout epithelium also showed reduced expression of markers of differentiated colonic epithelium and elevated expression of progenitor cell signaling. Thus, the transcriptional data were consistent with increased regenerative signaling in TNFR2-knockout epithelium, suggesting that TNFR2 has a role in restraining the relatively undifferentiated regenerative state.
Project description:H3K27me3 statuses were analyzed in normal mouse colonic epithelial cells and in those exposed to DSS-induced colitis, and aberrant changes of H3K27me3 by DSS-induced colitis were identified.
Project description:In the present study, we demonstrated that mice deficient in chemerin or IEC-specific CMKLR1 expression were highly susceptible to DSS-induced colitis and subsequent tumorigenesis, which was reversed by suppressing colonic neutrophilic inflammation using CXCR2 inhibitor. Surprisingly, we found that lack of the Chemerin-CMKLR1 signaling specifically reduced colonic epithelial expression of lactoperoxidase (LPO), an epithelial peroxidase which could utilize H2O2 to oxidase thiocyanates to antibiotic compound (Bafort et al., 2014). Importantly, we demonstrated that impaired epithelial LPO expression accounted for outgrowth of potentially pathogenic Gram-negative bacteria following epithelial injury, which led to overproduction of CXCL1/2 and pathological neutrophilic inflammation in mice with epithelial Chemerin-CMKLR1 signaling deficiency. Finally, lack of epithelial Chemerin-CMKLR1 signaling impaired early host defense against enteric bacteria, which was reversed by LPO supplementation. Taken together, our study uncovers a critical role of epithelial Chemerin-CMKLR1 signaling in restricting pathological colonic neutrophilia via potentiating LPO-mediated epithelial innate defense, thereby rendering protection against microbiota-driven colitis and tumorigenesis.
Project description:We determined changes in enhancer chromatin that occur during colonic inflammation, found that dynamic chromatin regions are enriched for HNF4A binding motirfs, and then measured HNF4A binidng by ChIP-seq in each condition. Examination of H3K27ac histone modification in normal and DSS-treated colon, examination of HNF4A binding by ChIP-seq in normal and DSS-treated colon epithelium
Project description:We compared the transcriptional signatures of the colonic mucosa from control mice (WT) versus mice deficient for the epithelial pantetheinase Vnn1 (Vnn1KO) or overexpressing Vnn1 specifically in intestinal epithelial cells (VIVA transgenic mice), during the development of DSS-induced colitis.
Project description:BACKGROUND: Peroxisome proliferator-activated receptor g (PPAR g) is a nuclear receptor whose activation has been shown to modulate macrophage and epithelial cell-mediated inflammation. The objective of this study was to use a systems approach for investigating the mechanism by which the deletion of PPAR g in epithelial cells modulates the severity of dextran-sodium sulfate (DSS)-induced colitis, immune cell distribution and global gene expression. RESULTS: The deficiency of PPAR g in epithelial cells does not significantly affect disease activity or body weight but worsens colon histopathlogy. WT mice have greater CD4+IL10+ T cells and fewer MHC II+ macrophages in mesenteric lymph nodes. Global gene expression analysis reveals greater changes after 7 days of DSS challenge (compared to 2 days). Colonic mucosa from VC- (WT) and VC+ (PPARg knock-out in epithelial cells) mice were sampled at 0 (no DSS), 2, and 7 days of DSS-induced experimental colitis
Project description:We reported the gene expression profiles of hCYP1A mouse colitis epithelial tissues on Day 1, 3 and 7 after the treatment with DSS or DSS/PhIP for 5 days.
Project description:The lack of suitable animal models reflecting chronically relapsing inflammation and tissue remodeling have hindered fibrosis research in inflammatory bowel diseases (IBD). This study investigated changes in connective tissue in a chronic murine model using different cycles of dextran sodium sulphate (DSS) to mimic the relapsing nature of the disease. We used whole gene expression arrays to study differences in colonic gene expression levels between acute and more chronic DSS colitis, Acute and chronic relapsing colonic inflammation was induced in C57BL6 female mice using several cycles of exposure to DSS in drinking water, followed by recovery phases. Total RNA, extracted from snap frozen colon from five mice per condition was used to analyze mRNA expression via Affymetrix Mouse Gene 1.0 ST arrays.